This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. The evolution of drug resistant strains poses a significant challenge for effective long-term treatment of human immunodeficiency virus type 1 (HIV-1) infection. One counter-measure against resistant strains is treatment with novel therapeutics. Several areas of HIV replication are potential targets for the development of new therapies. The goal of our research is to elucidate the assembly and transport of the HIV preintegration complex (PIC) to aid in the development of novel antiretroviral therapeutics. PICs are large viral DNA complexes formed during early HIV-1 infection of cells that target the viral DNA into the nuclei of cells after reverse transcription. Due to challenges in producing and purifying sufficient quantities of PICs there is limited understanding of their composition, assembly, and mechanism of the transport. Consequently, there are no inhibitors of PICs in development. The objective of our studies is to identify and characterize novel cellular components of HIV-1 PICs. We have undertaken two ambitious strategies to identify PIC-associated cellular proteins. First is a targeted proteomic analysis of PICs partially purified by velocity gradient centrifugation. Second, is a proteomic analysis of PICs affinity purified by specific biotinylation of HIV-1 proteins. Using both methods we have identified several candidate HIV dependency factors (HDFs). Candidate HDFs will be assessed for their interaction with HIV components and their role in HIV replication. Successful completion of these studies will advance the understanding of early events of HIV replication and discover new targets for the development of antiviral therapies.